After the sacrifice was completed, Plutarch[1410] tells us that the foreheads of the two youths were touched with the bloody knife that had slain the victims, and the stain was then wiped off with wool dipped in milk, after which the youths had to laugh. This has often been supposed to indicate an original human sacrifice[1411], the he-goats being substituted for human victims, and the death of the latter symbolized by the smearing with their blood. This explanation might be admissible if this were the only feature of the ceremony; but it is so entirely out of keeping with those that follow—the wearing of the skins and the running—that it is preferable to look for another before adopting it. At the same time it may be observed that no reasonable hypothesis can be ruled out of court where our knowledge of the rite is so meagre and so hard to bring satisfactorily into harmony with others occurring among other peoples[1412]. There is a curious passage in Apollonius Rhodius[1413], where purification from a murder is effected by smearing the hands of the murderer with the blood of a young pig, and then wiping it off ἄλλοις χύτλοισι; and the Scholiast on the lines describes a somewhat similar method of purification which was practised in Greece. This would raise a presumption that the youths were not originally the victims at the Lupercalia, but rather the slayers; and that they had to be purified from the guilt of the blood of the sacrosanct victim[1414]. When this was done they became one with the victim and the god by the girding on of the skins, and were able to communicate the new life thus acquired in the course of their lustratio of the city by means of the strips of skin to the women who met them. This explanation is open to one or two objections; for example, it hardly accounts for the laughter of the youths, unless we are to suppose that it was an expression of joy at their release from blood-guiltiness[1415]. And we have indeed no direct evidence that the youths were ever themselves the sacrificers, though the collateral evidence on this point, as I have already said, seems to be fairly strong[1416]. Yet I cannot but think that the true significance of the essential features of the ceremony is to be looked for somewhere in the direction thus indicated.